Acoustic generators, typified by piezoelectric speakers, are conventionally known to be used as small and thin speakers. Such acoustic generators can be used as speakers built in electronic devices including mobile phones and flat televisions.
An acoustic generator includes, for example, a rectangular frame body, a film stretched across the frame body, and a piezoelectric vibrating element provided on the film (see Patent Literature 1). This is configured such that the film having the outer edge portion supported by the frame body is excited, and the resonance of the film is used to generate sound.